All major textures in the game were increased to 400%+ of their original pixels, sharpened, and had some detail added. Then new normal maps were generated to take advantage of the greater detail, which results in a significant improvement over the original graphics. This enjoys 0% compression files, which helps offset the fact that larger files requires more system resources.
This major gameplay changer will alter many aspects of the game, to improve continuity, remove errors, and increase immersion. Thousands of variables were changed to improve the game and remove some of the bugs and logical errors (bad game design is not a bug). See the 13 page Readme file for full details on the changes broken down by group. Basically: Reweighs everything, rebalances all weapons and armor (clothes, hats, etc), redoes reloading, adds many recipes (only logical ones), and much more.